Open cable set-top box diagnosing system and method thereof

ABSTRACT

An open cable set-top box diagnosing system in which a point of deployment (POD), separated from a main circuit unit, having a newly defined interface is used to check an operation state of an open cable set-top box, transmits the checked state to a predetermined server, according to which the operation state of the open cable set-top box is diagnosed. The open cable set-top box diagnosing system includes an open cable set-top box  400 B for checking its own operation state by using a diagnosis resource by a communication protocol between a point of deployment (POD) separated from the main circuit unit and the main circuit, and a head end  400 A for providing a service corresponding to a request signal received from the open cable set-top box  400 B or providing a broadcast program to the open cable set-top box, and checking the operation state of the open cable set-top box.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to an open cable set-top box ofwhich a point of deployment (POD) is separated from a main circuit unit,and more particularly to an open cable set-top box diagnosing system inwhich the POD, separated from a main circuit unit, having a newlydefined interface is used to check an operation state of an open cableset-top box, transmits the checked state to a predetermined server,according to which the operation state of the open cable set-top box isdiagnosed, and a method thereof.

[0003] 2. Description of the Background Art

[0004] Recently, a digital cable set-top box becomes popular, which isconnected with a cable head end, producing a program for a digitalcable, by cable. The digital cable set-top box makes a bidirectionalcommunication with the cable head end in a manner that it receives anA/V broadcast program from the cable head end through an inband (IB),and transmits a user's request to the cable head end through an out ofband (OOB) and receives a corresponding service to be displayed.

[0005]FIG. 1 is a schematic block diagram showing a construction of ageneral digital cable set-top box.

[0006] As shown in the drawing, a digital cable set-top box 100 includesa tuner 11 for tuning a receive frequency to be able to receive an A/Vbroadcast program corresponding to a frequency of a channel desired by auser from a cable head end (not shown); a QAM (Quadrature AmplitudeModulation) demodulator 12 for receiving and demodulating an A/Vbroadcast program tuned by the tuner 11; a conditional access unit (CAU)14 for receiving the demodulated signal from the QAM demodulator 12according to a pre-set condition; a TP (transport) demultiplexer 15 forprocessing the signal outputted from the CAU 14 and outputting a datastream; an MPEG decoder 17-1 and an AC-3 decoder 17-2 for decoding thedata stream outputted from the TP demultiplexer 15 and outputting videosignals and audio signals; an OOB processing unit 13 for receiving thebroadcast program information such as a channel tuning or a programguidance from the tuner 11 through the OOB and processing it; and a CPU16 for receiving the signal processed by the OOB processing unit 13 andcontrolling the CAU 14 and the TP demultiplexer 15.

[0007] The OOB processing unit 13 includes an OOB receiver 13-1 forreceiving the signal outputted from the tuner 11; an OOB protocolprocessor 13-3 for processing a protocol of the signal processed by theOOB receiver 13-1 and outputting it to the CPU 16; and an OOBtransmitter 13-2 for processing the signal outputted from the OOBprotocol processor 13-3 and outputting it to the tuner 11.

[0008] The operation of the digital cable set-top box of theconventional art constructed as described above will now be explained.

[0009] When power is supplied to the digital cable set-top box, thetuner 11 receives an A/V broadcast program signal from the cable headend, tunes its frequency so as for a user to receive the A/V broadcastprogram, and outputs the tuned A/V broadcast program signal to the QAMdemodulator 12.

[0010] Then, the QAM demodulator 12 QAM-demodulates the A/V broadcastprogram signal and the QAM-demodulated signal to the CAU 14.

[0011] After the CAU 14 receives the QAM-demodulated signal, in casethat the QAM-demodulated signal is in an scrambled state, the CAU 14descrambles the QAM-demodulated signal according to a conditional accesskey (CAK) outputted from the CPU 16 and outputs it to the TPdemultiplexer 15.

[0012] Then, the TP demultiplexer 15 separates a video packet and anaudio packet of the descrambled signal and outputs them to the videodecoder 17-1 and the audio decoder 17-2.

[0013] The video decoder 17-1 clears an over head (i.e., various headerinformation or starting code, etc.) from the video packet and performsvariable-length decoding (VLD) for the pure data information. Then, thedecoded information undergoes inverse-quantizing, inverse-discretecosine transforming and motion compensating using a motion vector, isrestored as a pixel value of the original screen and outputted to themonitor.

[0014] The audio decoder 17-2 decodes the audio packet and outputs it toa speaker, by using an AC-3 algorithm.

[0015] Subscriber managing server systems connected with the cable headend manages subscribers connected with the cable head end, receivessubscriptions from subscribers who desire to receive a paid programprovided for a paid TV or a paper view and transmits informationcorresponding to the paid program to the subscribers, and manages andoperates the network on the whole.

[0016] When the subscriber registers at the subscriber managing serversystem, he or she is given a password from the subscriber managingserver system. The paid program is provided from the head end to theset-top box as the subscriber inputs the password to his or her set-topbox.

[0017] The subscriber managing server system renders the head end totransmit a diagnosis command signal to the set-top box, therebydiagnosing the operation state of the subscriber's set-top box. That is,when the OOB receiver of the set-top box receives the diagnosis commandsignal from the head end, the set-top box operates its ownself-diagnosis program to diagnose whether there is an error in eachcircuit unit of the set-top box and transmits the diagnosis result tothe head end through the OOB transmitter.

[0018] Upon receipt of the diagnosis result of the set-top box, the headend transmits the diagnosis result to the subscriber managing serversystem and receives an instruction from the subscriber managing serversystem as necessary.

[0019] Since the communication standard is already set, the set-top boxis manufactured by a set-top box manufacturers in cooperation with acable system operator (SO). Accordingly, the cable SOs installs theset-top box only for the subscribers who order it. Thus, problems arisethat it is difficult to control production of the set-top box, there isa problem of a stock burden, and the set-top box is to be replacedwhenever the function of the set-top box is upgraded.

[0020] In order to solve the problems, the cable SOs set a standard suchas an ‘open cable’ for separating the CAU from the main circuit unit andmanufactures a set-top box without the CAU.

[0021] In detail, the open cable set-top box of the above concept ismanufacture in a manner that the point of deployment (POD) including theCAU that has been installed in the cable set-top box is separated fromthe main circuit unit of the set-top box, a standard interface protocolbetween the main circuit unit of the set-top box and the POD is defined,and an interface is included between the main circuit unit and the POD.

[0022] Accordingly, the set-top box manufacturer can manufacture theopen cable set-top box without a restriction, and users also canpurchase the open cable set-top box without a restriction.

[0023] Accordingly, the users may purchase the open cable set-top boxand the POD provided by the cable SOs and connect them, thereby viewingcable broadcasting.

[0024]FIG. 2 is a schematic block diagram showing a construction of anopen cable set-top box in accordance with the conventional art, whichincludes a main circuit unit 200, a point of deployment (POD) 300 and aninterface 201 for connecting the main circuit unit 200 and the PODmodule 300.

[0025] The main circuit unit 200 includes a tuner 21 for tuning areceive frequency to be able to receive an A/V broadcast programcorresponding to a frequency of a channel desired by a user from a cablehead end (not shown); a QAM (Quadrature Amplitude Modulation)demodulator 22 for receiving an A/V broadcast program tuned by the tuner11, demodulating it and outputting the demodulated QAM signal throughthe interface 201 to the POD module 300; a TP (transport) demultiplexer24 for processing the signal received through the interface 201 from thePOD module 300 and outputting a data stream; an MPEG decoder 26-1 and anAC-3 decoder 26-2 for decoding the data stream outputted from the TPdemultiplexer 24 and outputting video signals and audio signals; an OOBreceiver 23-1 for receiving the broadcast program information such as achannel tuning or a program guidance from the tuner 21 through the OOB,processing and outputting it through the interface 201 to the POD module300; an OOB transmitter 23-2 for receiving the signal through theinterface 201 from the POD module 300 and outputting it through the OOBto the tuner 21; and a CPU 25 for controlling each circuit unit of themain circuit unit 200 and communicating with the POD module 300 throughthe interface.

[0026] The POD 300 includes a CPU 34 for communicating with the CPU 25of the main circuit unit 200 and controlling the whole POD; a CAU 33 forreceiving the demodulated QAM from the QAM demodulator of the maincircuit unit 200, and descrambling the QAM-demodulated signal accordingto a conditional access key (CAK) outputted from the CPU 34 andoutputting it to the TP demultiplexer 24 in case that theQAM-demodulated signal is in a scrambled state; an OOB protocolprocessor 31 for communicating with the OOB receiver 23-1 and the OOBtransmitter 23-2 under the control of the CPU 34; and a TP demultiplexer32 for receiving the demodulated QAM and the signal from the OOBprotocol processor 31 and demultiplexing them.

[0027] In this respect, the POD uses a PCMCIA card.

[0028] The operation of the conventional open cable set-top boxconstructed as described above will now be explained.

[0029] When power is supplied to the open cable set-top box, an A/Vbroadcast program is inputted to the POD through the tuner and the QAMdemodulator, and the CAU of the POD descrambles and outputs the A/Vprogram to the TP demultiplexer 24 of the main circuit unit 200. Inother words, the CPU 34 of the POD interprets the command received fromthe head end through the OOB transmitter and OOB receiver of the maincircuit unit 200 and the OOB protocol processor and the TP demultiplexerof the POD and outputs the interpreted command through a data channeland an extended channel of the interface 201 to the CPU 25 of the maincircuit unit 200, so that the CPU 25 performs the command instructed bythe head end.

[0030] Or, the CPU of the POD transmits a request of a user through theOOB transmitter and the OOB receiver of the main circuit unit 200 andthe OOB protocol processor and the TP demultiplexer of the POD to thehead end, so that the user may receive his or her desired program.

[0031]FIG. 3 shows a communication protocol between the CPU of the PODand the CPU of the main circuit unit transmitted via the data channel.

[0032] As shown in the drawing, the communication protocol includes,from the bottom, a PC card physical layer, a PC card link layer, a PCcard transport sublayer, a generic transport sublayer and a sessionlayer, which are common with other communication protocol, and aresource layer which has different content. That is, the resource layergives and takes a software module such as an object to and from otherlayers to support execution of applications arranged at the upperportion of the resource layer.

[0033] The application performs communicating between the POD and themain circuit unit only by using resources included in the resourcelayer. Thus, whether the function of the POD interface can be extendedor not is determined depending on how the resources are defined.

[0034] For example, the below Table 1 shows kinds of resources definedin the current U.S. open cable standard. Resource DVS064 Part B OpenCable Resource Manager Yes Yes MMI Yes Yes Application information YesUpdated Low Speed Communication Yes Updated Conditional Access SupportYes Yes Smart Cart Reader Optional Optional Copy Protection No Yes HostControl-info. Resource Yes Updated Extended Channel Support No YesGeneric IPPV Support No Yes Specific Application Support No Yes

[0035] As shown in Table 1, the resources are defined only to supportapplications used by users without including any resources to diagnose adefective state or a defective position when the set-top box isdisordered.

[0036] Thus, the open cable set-top box being on the market does notinclude such a resource having a diagnosis function in the PODinterface, it is not possible for the POD to diagnose whether theset-top box is out of order.

[0037] In addition, in case that the open cable set-top box is out oforder and thus the user is not able to view a desired broadcast program,since the user has no idea of which one of the POD and the main circuitunit of the set-top box has been broken down, the user could hardlyjudge to which one of the cable SO and the set-top box manufacturer heor she reports the disorder.

[0038] Therefore, since the head end, which provides the service to theopen cable set-top box, is unable to recognize the disorder of thesubscriber set-top box in advance, its competitive edge is degraded withrespect to the satellite broadcast producers and ground wave broadcastproducers.

SUMMARY OF THE INVENTION

[0039] Therefore, an object of the present invention is to provide anopen cable set-top box diagnosing system in which a diagnosis resourcefor checking an operation state of a set-top box is added to resourcesdefined for POD interfacing so that a cable head end can diagnose theoperation state of a set-top box through a POD, and its method.

[0040] Another object of the present invention is to provide an opencable set-top box diagnosing system in which, when a set-top box getsout of order, diagnosis information on the defective set-top box istransmitted to a set-top box manufacturer on a real time basis through anetwork, so that the troubled set-top box can be easily settled, and itsmethod.

[0041] To achieve these and other advantages and in accordance with thepurpose of the present invention, as embodied and broadly describedherein, there is provided an open cable set-top box diagnosing system inwhich a cable head end checks an operation state of a set-top boxthrough a point of deployment (POD) by using a diagnosis resource forchecking an operation state of the set-top box of a resource layerdefined for interface between the point of deployment and the set-topbox in an open cable set-top box of which the POD and the set-top boxare separated, and the cable head end is connected with a manufacturerof the set-top box by bidirectional network.

[0042] To achieve the above objects, there is also provided an opencable set-top box diagnosing system including an open cable set-top box400B for checking its own operation state by using a diagnosis resourceby a communication protocol between a point of deployment (POD)separated from the main circuit unit and the main circuit, and a headend 400A for providing a service corresponding to a request signalreceived from the open cable set-top box 400B or providing a broadcastprogram to the open cable set-top box, and checking the operation stateof the open cable set-top box.

[0043] To achieve the above objects, there is also provided an opencable set-top box diagnosing method including a step in which when acommand for checking the operation state of the set-top box is inputtedfrom the head end, the point of deployment (POD) requests system stateinformation from the set-top box, and when the system state informationis received from the set-top box, the POD transmits it to the head end;a step in which the head end checks whether there is an error in theset-top box on the basis of the received system state information andrequests detailed information on a defective sub-system from the POD incase that there is an error in the set-top box; and a step in which thePOD requests detailed information of the defective sub-system from theset-top box, and when detailed information on the defective sub-systemis received from the set-top box, the POD transmits the detailedinformation to the head end.

[0044] To achieve the above objects, there is also provided an opencable set-top box diagnosing method including the steps of: requestingstate information on the open cable set-top box according to the commandfor checking the operation state of the open cable set-top box receivedfrom the head end; diagnosing whether there is an error in the opencable set-top box on the basis of the state information; and requestingdetailed information on circuit units of a defective open cable set-topbox in case that there is an error in the open cable set-top box.

[0045] The foregoing and other objects, features, aspects and advantagesof the present invention will become more apparent from the followingdetailed description of the present invention when taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this specification, illustrate embodiments of theinvention and together with the description serve to explain theprinciples of the invention.

[0047] In the drawings:

[0048]FIG. 1 is a schematic block diagram showing a construction of ageneral digital cable set-top box;

[0049]FIG. 2 is a schematic block diagram showing a construction of anopen cable set-top box in accordance with a conventional art;

[0050]FIG. 3 illustrates a communication protocol between a POD and amain circuit unit in accordance with the conventional art;

[0051]FIG. 4 is a schematic block diagram showing a construction of anopen cable set-top box diagnosing system in accordance with the presentinvention;

[0052]FIG. 5 shows an example of coding of a Diag_open_req() object;

[0053]FIG. 6A shows an example of coding of Diag_open_cnf() object;

[0054]FIGS. 6B and 6C show Datdtype_id value, length and Sub-system_idpreviously defined in the Diag_open_cnf() object;

[0055]FIG. 7 shows an example of coding of a Diag_sta_req() object;

[0056]FIG. 8 shows an example of coding of a Diag_stat_cnf() object;

[0057]FIG. 9 shows an example of coding of a Diag_stat_req() object;

[0058]FIG. 10A shows an example of coding of a Diag_data_cnf() object;

[0059]FIG. 10B shows an example of coding of a Diag_data_cnf() object;and

[0060]FIG. 11 is a flow chart of a method for diagnosing operation stateof the open cable set-top box in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] Reference will now be made in detail to the preferred embodimentsof the present invention, examples of which are illustrated in theaccompanying drawings.

[0062]FIG. 4 is a schematic block diagram showing a construction of anopen cable set-top box diagnosing system in accordance with the presentinvention.

[0063] As shown in the drawing, the open cable set-top box diagnosingsystem of the present invention includes a head end 400A for providing abroadcast program, subscriber managing servers (S1, S2, . . . , Sn)connected with the head end 400A and an open cable set-top box 400Bconnected with the head end 400A.

[0064] The open cable set-top box 400B includes a main circuit unit 401,a point of deployment (POD) 403 and an interface 402 for connecting themain circuit unit 401 and the POD 403.

[0065] The main circuit unit 401 includes a tuner 41 for tuning areceive frequency to be able to receive an A/V broadcast programcorresponding to a frequency of a channel desired by a user from a cablehead end 400A; a QAM (Quadrature Amplitude Modulation) demodulator 42for receiving an A/V broadcast program tuned by the tuner 41,demodulating it and outputting the demodulated QAM signal through theinterface 402 to the POD 403 through the IB; a TP (transport)demultiplexer 44 for processing the signal received through theinterface 402 from the POD 403 and outputting a data stream; an MPEGdecoder 46-1 and an AC-3 decoder 46-2 for decoding the data streamoutputted from the TP demultiplexer 44 and outputting video signals andaudio signals; an OOB receiver 43-1 for receiving the broadcast programinformation such as a channel tuning or a program guidance from thetuner 41 through the OOB, processing and outputting it through theinterface 402 to the POD 403; an OOB transmitter 43-2 for receiving thesignal through the interface 402 from the POD 403 and outputting itthrough the OOB to the tuner 41; and a CPU 45 for controlling eachcircuit unit of the main circuit unit 401 and communicating with the POD403 through the interface.

[0066] The POD 403 includes a CPU 54 for communicating with the CPU 45of the main circuit unit 401 and controlling the whole POD; a CAU 53 forreceiving the demodulated QAM from the QAM demodulator of the maincircuit unit 401, and descrambling the QAM-demodulated signal accordingto a conditional access key (CAK) outputted from the CPU 54 andoutputting it to the TP demultiplexer 44 in case that theQAM-demodulated signal is in a scrambled state; an OOB protocolprocessor 51 for communicating with the OOB receiver 43-1 and the OOBtransmitter 43-2 under the control of the CPU 54; and a TP demultiplexer52 for receiving the demodulated QAM and the signal from the OOBprotocol processor 51 and demultiplexing them.

[0067] In the present invention, the POD uses a PCMCIA card.

[0068] The operation of the open cable set-top box of the presentinvention constructed as described above will now be explained.

[0069] When power is supplied to the open cable set-top box, an A/Vbroadcast program is inputted to the POD through the tuner and the QAMdemodulator, and the CAU of the POD descrambles and outputs the A/Vprogram to the TP demultiplexer 44 of the main circuit unit 401. Inother words, the CPU 54 of the POD interprets the command received fromthe head end through the OOB transmitter and OOB receiver of the maincircuit unit 401 and the OOB protocol processor and the TP demultiplexerof the POD and outputs the interpreted command through a data channeland an extended channel of the interface 402 to the CPU 45 of the maincircuit unit 401, so that the CPU425 performs the command instructed bythe head end.

[0070] Or, the CPU of the POD transmits a request of a user through theOOB transmitter and the OOB receiver of the main circuit unit 401 andthe OOB protocol processor and the TP demultiplexer of the POD to thehead end, so that the user may receive his or her desired program.

[0071] As shown in FIG. 3, the communication protocol between the CPU ofthe POD and the CPU of the main circuit unit transmitted via the datachannel includes, from the bottom, a PC card physical layer, a PC cardlink layer, a PC card transport sublayer, a generic transport sublayerand a session layer, and a resource layer.

[0072] Especially, the resource layer includes a resource for diagnosingthe operation state of the set-top box, so that the set-top box candiagnose its own operation state.

[0073] In other words, by adding a diagnosis resource for checking theoperation state of the set-top box to the resources defined for the PODinterface, the cable head end is able to check the operation state ofthe set-top box through the POD module, so that the cable SOs can managethe subscriber set-top box, recognizes a necessary step in advance andquickly cope with it.

[0074] Accordingly, in case that the set-top box has an error, the cablehead end informs a corresponding set-top manufacturer of the informationon the defective set-top box on a real time basis through a network, sothat it can be repaired or replaced rapidly.

[0075] The diagnosis resource added to the resource layer of the PODinterface can be described in detail.

[0076] The diagnosis resource should include defined objects to be usedto exchange diagnosis data between the POD and the set-top box. That is,the objects determine a specific ID information data format todiscriminate subscriber set-top box such as a name of a manufacturer, aname of a model or a serial number, divides the whole system tosub-systems, a functional unit to be checked, and gives an ID, anddefines states of each sub-system.

[0077] For example, the objects belonging to the diagnosis resource ofthe present invention are as follows.

[0078] Diag_open_req() POD→set-top box: requesting to open diagnosissource

[0079] Diag_open_cnf() POD←set-top box: replying for sub-systemconstruction information of the set-top box

[0080] Diag_stat_req() POD→set-top box: requesting a system state

[0081] Diag_state_cnf() POD←set-top box: replying whether there is anerror in the system

[0082] Diag_data_req() POD→set-top box: requesting detailed informationin case that there is an error in the system

[0083] Diag_data_cnf() POD<→set-top box: replying to the defectivesub-system state

[0084]FIGS. 5 through 10 illustrate examples of codings to implement theobjects.

[0085]FIG. 5 shows an example of coding of a Diag_open_req() object;FIG. 6A shows an example of coding of Diag_open_cnf() object; FIGS. 6Band 6C show Datdtype_id value, length and Sub-system_id previouslydefined in the Diag_open_cnf() object; FIG. 7 shows an example of codingof a Diag_sta_req() object; FIG. 8 shows an example of coding of aDiag_stat_cnf() object; FIG. 9 shows an example of coding of aDiag_stat_req() object; FIG. 10A shows an example of coding of aDiag_data_cnf() object; and FIG. 10B shows an example of coding of aDiag_data_cnf() object.

[0086]FIG. 11 is a flow chart of a method for diagnosing operation stateof the open cable set-top box in accordance with the present invention.

[0087] With reference to FIG. 11, after the OOB transmitter and receiverof the main circuit unit 401 connected with the head end interprets thecommand received from the head end, the CPU 54 of the POD 403 rendersthe OOB transmitter and receiver to communicate with the CPU 45 of themain circuit unit 401 through the data channel and the extended channelthrough the interface 402 to perform the command instructed by the headend, or transmits contents inputted by the user and the stateinformation of each circuit unit of the set-top box through the OOBtransmitter and receiver of the main circuit unit 401 connected with thehead end.

[0088] In detail, when the cable head end requests various IDinformation related to the set-top box and the information on thesub-system construction from the POD (1), the POD requests the maincircuit unit of the set-top box to open the diagnosis resource by usingthe Diag_open_req() object as shown in FIG. 5 (2).

[0089] Then, the main circuit unit transmits the information requestedby the POD obtained on the basis of the pre-set input information byusing the Diag_open_cnf() object as shown in FIG. 6 (3).

[0090] Accordingly, the POD transmits the various ID information relatedto the set-top box and information on the sub-system construction to thecable head end (4).

[0091] Thereafter, when the cable head end transmits the command forperiodically checking and reporting the operation state of the set-topbox to the POD (5), the POD checks the operation state of the set-topbox through the diagnosis resource defined in the POD interface andreports it to the cable head end.

[0092] That is, the POD requests the system state from the set-top boxby using the Diag_stat_req() object as shown in FIG. 7 (6), the maincircuit unit of the set-top box, which has periodically checked theoperation state of the set-top box, transmits the system state of theset-top box to the POD by using the Diag_stat_cnf() object as shown inFIG. 8 (7).

[0093] Then, the POD transmits the system state of the set-top box tothe cable head end (8), and the cable head end checks whether there isan error in the system on the basis of the received information (9).

[0094] In case that there is no error in the system of the set-top box,the cable head end repeatedly checks the operation state of the set-topbox (5, 6, 7, 8 and 9), while, in case that there is an error in thesystem, the cable head end requests detailed state information on thedefective sub-system from the POD (10).

[0095] Then, the POD requests detailed information on the sub-system ofthe defective set-top box from the main circuit unit of the set-top boxby using the Diag_data_req() object as shown in FIG. 9 (11).

[0096] Then, the main circuit unit of the set-top box transmits thestate information of the sub-system of the defective set-top box to thePOD by using the Diag_data_cnf() object as shown in FIG. 10 (12), andthe POD transmits the received state information of the sub-system ofthe set-top box to the cable head end (13).

[0097] While the head end is checking the operation state of the set-topbox, in case that the head end is informed of the defective set-top boxfrom the POD, the head end registers the informed content with thesubscriber managing servers (S1, S2, . . . , Sn) and informs thecorresponding manufacturer of the defective set-top box of the ID of thedefective set-top box and the abnormal operation state content on thereal time basis.

[0098] Accordingly, various service (i.e., early report on a trouble,repairing or replacing, etc) for the troubled set-top box can beeffectively and quickly provided from an A/S service person ofmanufacturers to consumers.

[0099] In addition, the cable head end is able to detect the trouble ofthe POD as occurring, and an error occurs in the POD, the cable head endreports the error to an A/S service person of the cable head end itself,so that its own A/S service person can settle the problem.

[0100] As so far described, the open cable set-top box diagnosing systemand method of the present invention, the interface for diagnosing theset-top box function is added to the POD interface of the digital cableset-top for an open cable, so that the cable head end can manage the IDinformation to discriminate set-top boxes owned by each subscriber andthe operation state information of each set-top box on the real timebasis.

[0101] In addition, in case that the set-top box or the POD is troubled,the diagnosis information on the troubled set-top box is transmitted tothe corresponding set-top box manufacturer, so that the troubled set-topbox or the POD can be quickly repaired or replaced.

[0102] As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the meets and bounds of theclaims, or equivalence of such meets and bounds are therefore intendedto be embraced by the appended claims.

What is claimed is:
 1. An open cable set-top box diagnosing systemwherein a cable head end checks an operation state of a set-top boxthrough a point of deployment (POD) by using a diagnosis resource forchecking an operation state of the set-top box of a resource layerdefined for interface between the point of deployment and the set-topbox in an open cable set-top box of which the POD and the set-top boxare separated, and the cable head end is connected with a manufacturerof the set-top box by bidirectional network.
 2. The system according toclaim 1 , wherein the cable head end periodically checks the operationstate of the set-top through the POD module and informs a correspondingset-top box manufacturer of the diagnosis information on a troubledset-top on a real time basis.
 3. The system according to claim 1 ,wherein the diagnosis resource previously defines objects to be used toexchange diagnosis data between te POD and the set-top box determines aspecific ID information data format to discriminate subscriber set-topboxes, divides the whole system into sub-systems, that is, functionalunits to be checked and gives each sub-system an ID, and defines thestates of each sub-system so that the state information of eachsub-system is exchanged between sub-systems as a data of an object. 4.An open cable set-top box diagnosing method comprising: a step in whichwhen a command for checking the operation state of the set-top box isinputted from the head end, the point of deployment (POD) requestssystem state information from the set-top box, and when the system stateinformation is received from the set-top box, the POD transmits it tothe head end; a step in which the head end checks whether there is anerror in the set-top box on the basis of the received system stateinformation and requests detailed information on a defective sub-systemfrom the POD in case that there is an error in the set-top box; and astep in which the POD requests detailed information of the defectivesub-system from the set-top box, and when detailed information on thedefective sub-system is received from the set-top box, the POD transmitsthe detailed information to the head end.
 5. The method according toclaim 1 , further comprising a step in which in case that informationthat there is an error in the set-top box is received, the head endregisters the received error information with the subscriber managingserver and informs a manufacturer of the corresponding set-top box andits subscriber of the set-top box ID and the trouble through a networkon a real time basis.
 6. The method according to claim 5 , wherein whenthe cable head end requests various ID information related to theset-top box and information on the sub-system construction from the POD,the POD requests the set-top box to open the diagnosis resource, theset-top box transmits the sub-system construction information of theset-top box by using the pre-set input information to the POD, and thePOD transmits the same to the cable head end.
 7. An open cable set-topbox diagnosing system comprising: an open cable set-top box for checkingits own operation state by using a diagnosis resource by a communicationprotocol between a point of deployment (POD) separated from the maincircuit unit and the main circuit; and a head end for providing aservice corresponding to a request signal received from the open cableset-top box or providing a broadcast program to the open cable set-topbox, and checking the operation state of the open cable set-top box. 8.The system according to claim 7 , wherein the main circuit unitcomprising: a tuner for tuning a receive frequency to be able to receivea broadcast program corresponding to a frequency of a channel desired bya user from a cable head end; a demodulator for receiving an broadcastprogram tuned by the tuner, demodulating it and outputting thedemodulated signal to the POD through the IB; a demultiplexer forprocessing the signal received from the POD and outputting a datastream; a decoder for decoding the data stream outputted from thedemultiplexer and outputting it to a display and a speaker; an OOBreceiver for receiving the broadcast program information from the tunerthrough an OOB, processing and outputting it to the POD; an OOBtransmitter for receiving the signal from the POD and outputting itthrough the OOB to the tuner; and a CPU for controlling each circuitunit of the main circuit unit.
 9. The system according to claim 7 ,wherein the POD comprising: a CPU 54 for controlling each circuit unitof the POD; a conditional access unit for receiving the demodulatedsignal from the main circuit unit, and descrambling the demodulatedsignal according to a conditional access key (CAK) outputted from theCPU; an OOB protocol processor for transmitting and receiving thebroadcast program related information to and from the main circuit unitunder the control of the CPU; and a demultiplexer for receiving thedemodulated signal and the signal from the OOB protocol processor anddemultiplexing them under the control of the CPU.
 10. The systemaccording to claim 7 , wherein the open cable set-top box includes aninterface to connect the main circuit unit and the POD.
 11. The systemaccording to claim 7 , further comprising subscriber managing serversbeing connected with the head end, for receiving the operation state ofthe open cable set-top box transmitted from the head end to manage theopen cable set-top boxes.
 12. The system according to claim 7 , whereinthe POD is a PCMCIA card.
 13. An open cable set-top box diagnosingmethod comprising the steps of: requesting state information on the opencable set-top box according to the command for checking the operationstate of the open cable set-top box received from the head end;diagnosing whether there is an error in the open cable set-top box onthe basis of the state information; and requesting detailed informationon circuit units of a defective open cable set-top box in case thatthere is an error in the open cable set-top box.
 14. The methodaccording to claim 13 , wherein, in the step of requesting stateinformation, the head end requests ID information related to the openset-top box and information on the sub-system construction.
 15. Themethod according to claim 13 , wherein, in the step of requesting stateinformation, the head end periodically requests state information of theopen set-top box.
 16. The method according to claim 13 , wherein, in thestep of requesting detailed information, the detailed information isrequested because of an abnormal operation of the open cable set-topbox.
 17. The method according to claim 13 , further comprising a step ofinforming a manufacturer of the corresponding open set-top box or asubscriber managing server of the detailed information on a real timebasis.